scholarly journals The Organization and Polarity of Pollen Mother Cells of Triticum Aestivum

1972 ◽  
Vol 11 (3) ◽  
pp. 699-711
Author(s):  
G. A. DOVER
Keyword(s):  
Triticum Aestivum ◽  
Ploidy Levels ◽  
Pollen Mother Cells ◽  
Time Of Application ◽  
Naturally Occurring ◽  
Aegilops Sharonensis ◽  
Pollen Types ◽  
Tapetal Cells ◽  
Meiotic Spindles ◽  
Mother Cells

Colchicine has been applied to young developing anthers of Triticum aestivum at varying stages of maturity from the last premeiotic mitoses of the archesporial and tapetal cells to the second meiotic divisions of the pollen mother cells. The developmental stage of the archesporium at which colchicine took effect was determined by cytological examination of the ploidy levels of the nuclei of the adjacent tapetal cells. The type of pollen abnormality induced depended on the time of application and the concentration of colchicine. Uninucleate monads with 4 randomly positioned pores and uninucleate monads without pores were obtained with 0.5% colchicine. Multipored polyads and multipored uninucleate monads were observed together in anthers treated with 0.01% colchicine. Naturally occurring aberrant pollen types in hybrids of Triticum aestivum x Aegilops mutica or T. aestivum x Aegilops sharonensis have revealed a constant relationship between the disposition of the meiotic spindles and the siting of the pollen pores. The colchicine-induced abnormalities have further clarified the nature of this relationship leading to the interpretation that both the positioning of the spindles and the siting of the pores are predetermined by events taking place in the premeiotic interphase at a time just after the last mitosis of the pollen mother cells and the penultimate mitosis of the tapetum. A reorganization of the archesporial cells (sensitive to colchicine) possibly occurs at this time. Various subsequent meiotic events are dependent on the reorganization. Two of these events - the organization of meiotic spindles and the establishment of pollen symmetry - are discussed.

Genotoxic Effects of Superconducting Static Magnetic Fields (SMFs) on Wheat (Triticum aestivum) Pollen Mother Cells (PMCs)

2007 ◽  
Vol 9 (2) ◽  
pp. 241-247 ◽  
Author(s):  
Zhang Pingping ◽  
Yin Ruochun ◽  
Chen Zhiyou ◽  
Wu Lifang ◽  
Yu Zengliang
Keyword(s):  
Triticum Aestivum ◽  
Magnetic Fields ◽  
Genotoxic Effects ◽  
Static Magnetic Fields ◽  
Pollen Mother Cells ◽  
Mother Cells

The duration of meiosis in pollen mother cells of wheat, rye and Triticale

1971 ◽  
Vol 178 (1052) ◽  
pp. 259-275 ◽  
Keyword(s):  
Triticum Aestivum ◽  
Dna Synthesis ◽  
Secale Cereale ◽  
Sampling Methods ◽  
Tritiated Thymidine ◽  
Pollen Mother Cells ◽  
Mother Cells

The duration of meiosis and its stages at 20 °C has been determined in wheat ( Triticum aestivum 2 n = 6 x = 42), in rye ( Secale cereale 2 n = 14) and in Triticale (2 n = 8 x = 56) by sampling methods and by timing the intervals between the pre-meiotic DNA synthesis and meiotic stages following the incorporation of tritiated thymidine. The results from all the methods used were in general agreement. Meiosis takes about 24 h in wheat, 21 h in Triticale and about 51 h in rye. The lengths of the meiotic stages relative to that of the division correspond reasonably well in the three forms studied but zygotene and pachytene were much longer in rye than in wheat and Triticale .

scholarly journals The Development and Meiotic Behavior of Asymmetrical Isochromosomes in Wheat

Genetics ◽  
1997 ◽  
Vol 145 (4) ◽  
pp. 1155-1160
Author(s):  
Adam J Lukaszewski
Keyword(s):  
Triticum Aestivum ◽  
Hexaploid Wheat ◽  
Triticum Aestivum L ◽  
Meiotic Metaphase ◽  
Meiotic Behavior ◽  
Pollen Mother Cells ◽  
Chromosome Arm ◽  
Mother Cells ◽  
Metaphase I

To determine which segments of a chromosome arm are responsible for the initiation of chiasmate pairing in meiosis, a series of novel isochromosomes was developed in hexaploid wheat (Triticum aestivum L.). These isochromosomes are deficient for different terminal segments in the two arms. It is proposed to call them “asymmetrical.” Meiotic metaphase I pairing of these asymmetrical isochromosomes was observed in plants with various doses of normal and deficient arms. The two arms of an asymmetrical isochromosome were bound by a chiasma in only two of the 1134 pollen mother cells analyzed. Pairing was between arms of identical length whenever such were available; otherwise, there was no pairing. However, two arms deficient for the same segment paired with a frequency similar to that of normal arms, indicating that the deficient arms retained normal capacity for pairing. Pairing of arms of different length was prevented not by the deficiency itself, but rather, by the heterozygosity for the deficiency. Whether two arms were connected via a centromere in an isochromosome or were present in two different chromosomes had no effect on pairing. This demonstrates that in the absence of homology in the distal regions of chromosome arms, even if relatively short, very long homologous segments may remain unrecognized in meiosis and will not be involved in chiasmate pairing.

scholarly journals Naturally Occurring Ecdysteroids in Triticum aestivum L. and Evaluation of Fenarimol as a Potential Inhibitor of Their Biosynthesis in Plants

2021 ◽  
Vol 22 (6) ◽  
pp. 2855
Author(s):  
Anna Janeczko ◽  
Jana Oklestkova ◽  
Danuše Tarkowská ◽  
Barbara Drygaś
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Triticum Aestivum L ◽  
Growth Conditions ◽  
Animal Kingdom ◽  
Experimental Conditions ◽  
P450 Monooxygenase ◽  
Naturally Occurring ◽  
Regulatory Effects ◽  
Potential Use

Ecdysteroids (ECs) are steroid hormones originally found in the animal kingdom where they function as insect molting hormones. Interestingly, a relatively high number of these substances can also be formed in plant cells. Moreover, ECs have certain regulatory effects on plant physiology, but their role in plants still requires further study. One of the main aims of the present study was to verify a hypothesis that fenarimol, an inhibitor of the biosynthesis of ECs in the animal kingdom, also affects the content of endogenous ECs in plants using winter wheat Triticum aestivum L. as a model plant. The levels of endogenous ECs in winter wheat, including the estimation of their changes during a course of different temperature treatments, have been determined using a sensitive analytical method based on UHPLC-MS/MS. Under our experimental conditions, four substances of EC character were detected in the tissue of interest in amounts ranging from less than 1 to over 200 pg·g−1 FW: 20-hydroxyecdysone, polypodine B, turkesterone, and isovitexirone. Among them, turkesterone was observed to be the most abundant EC and accumulated mainly in the crowns and leaves of wheat. Importantly, the level of ECs was observed to be dependent on the age of the plants, as well as on growth conditions (especially temperature). Fenarimol, an inhibitor of a cytochrome P450 monooxygenase, was shown to significantly decrease the level of naturally occurring ECs in experimental plants, which may indicate its potential use in studies related to the biosynthesis and physiological function of these substances in plants.

scholarly journals Male meiosis and pollen morphology in diploid Indonesian wild bananas and cultivars

The Nucleus ◽  
2021 ◽  
Author(s):  
Fajarudin Ahmad ◽  
Yuyu S. Poerba ◽  
Gert H. J. Kema ◽  
Hans de Jong
Keyword(s):  
Hybrid Sterility ◽  
Pollen Grains ◽  
Chromosome Analysis ◽  
Male Meiosis ◽  
Enzyme Treatment ◽  
Unreduced Gamete ◽  
Ploidy Levels ◽  
Scientific Disciplines ◽  
Sterile Pollen ◽  
Mother Cells

AbstractBreeding of banana is hampered by its genetic complexity, structural chromosome rearrangements and different ploidy levels. Various scientific disciplines, including cytogenetics, linkage mapping, and bioinformatics, are helpful tools in characterising cultivars and wild relatives used in crossing programs. Chromosome analysis still plays a pivotal role in studying hybrid sterility and structural and numerical variants. In this study, we describe the optimisation of the chromosome spreading protocol of pollen mother cells focusing on the effects of standard fixation methods, duration of the pectolytic enzyme treatment and advantages of fluorescence microscopy of DAPI stained cell spreads. We demonstrate the benefits of this protocol on meiotic features of five wild diploid Musa acuminata bananas and a diploid (AA) cultivar banana “Rejang”, with particular attention on pairing configurations and chromosome transmission that may be indicative for translocations and inversions. Pollen slides demonstrate regular-shaped spores except “Rejang”, which shows fertile pollen grains of different size and sterile pollen grains, suggesting partial sterility and unreduced gamete formation that likely resulted from restitutional meiotic divisions.

Chromosome localization of genes that control synchronous development of pollen mother cells in wheat

Caryologia ◽  
2003 ◽  
Vol 56 (3) ◽  
pp. 275-279 ◽  
Author(s):  
Wei Li ◽  
Jun Yang ◽  
You-Fu Pan ◽  
Guang-Qin Guo ◽  
Guo-Chang Zheng
Keyword(s):  
Chromosome Localization ◽  
Pollen Mother Cells ◽  
Synchronous Development ◽  
Mother Cells

An ultrastructural study of cytomixis in tobacco pollen mother cells

PROTOPLASMA ◽  
2011 ◽  
Vol 248 (4) ◽  
pp. 717-724 ◽  
Author(s):  
Sergey R. Mursalimov ◽  
Elena V. Deineko
Keyword(s):  
Ultrastructural Study ◽  
Pollen Mother Cells ◽  
Tobacco Pollen ◽  
Mother Cells
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